Semimetallic packing.



PATENTED MAR. 31'; 1,903.

,A, L. COLE. SEMIMETALLIC PACKING. APPLICATION. FILED 001'. 7, 1901.

N0 MODEL.

NITE

ATENT, FFICE.

ALBERT L. COLE, OF WEST NEWTON, MASSACHUSETTS, ASSIGNOR TO STAND- ARDPACKING MANUFACTURING COMPANY, A CORPORATION OF MAINE.

SEMIMETALLIC PACKING.

SPECIFICATION forming part of Letters Patent No, 723,831, dated March31, 1903.

Application filed October 7, I901. Serial No. 77,761. (No model.)

To all whom it may concern.-

Be it known that I, ALBERT L. COLE, a citi-. zen of the UnitedStates.residing at West Newton, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inSemimetallic Packing, of which the following is a specification,reference being had therein to the accompanying drawings.

My invention relates to improvements in semimetallic packing composed ofa core of shredded soft metal covered with rubber impregnated with alubricant and is designed for use on piston-rods and plungers in steam[5 or other engines or pumps in places where high pressures of steam andof other gases or fluids are used.

My invention has for its object the production of an efficient, anddurable packing, es-

2o pecially when subjected in use to high pressures.

The following is a clear description of my invention, reference beingmade to the 'accompanying drawings, in which- Figure l is a verticaltransverse section of a stuffing-box, showing the application of thepacking to a piston-rod. Fig. 2 is a transverse section on the line 2 2in Fig. 4 of the packing made in the round form.

a transverse section of packing made in the square form. Fig. 4 is alongitudinal vertical section on the line 4 4 in Fig. 2 and elevation ofthe packing madein the round form. Fig. 5 is a viewin perspective with asection cut away, showing the construction of the packing in sheet form.

Similarletters refer to similar parts throughout the several Views.

My semimetallic packing is m-ade as fol-' 4o lows: I first take a softflexible antifriction metal, such as Babbitt metal, which will not scorea piston-rod, and shred it by drawing out. These metallic shreds a a Iuse to form the metallic core A of my packing. The

shreds a a are bunched tightly together the desired size of the core Aand are then ready for the rubber covering B. If desired, the

core may be made of metal in the form of ribbons or blocks or anyother'shapeinstead of shreds. To make the covering B, I use crude rubberin a soft state and mix with it graphite or some other suitablelubricant and Fig. 3 is knead them together thoroughly until the rubberis well impregnated with the graphite.

.Heretofore in packings it has been impracticable to use rubber next tothe working parts on account of its corrosive elfect on those parts; butby mixing graphite with the rub her this dififiicultyis overcome and thegraphite acts as a lubricant and prevents the rubher covering, which isin contact with the working parts, adhering to or corroding those partseven when they become heated. There are no specified proportions inwhich to mix the rubber and the graphite; but I have found in myexperience that a covering consisting ofabout eighty-five per cent.-ofrubber and about fifteen per cent. 'of' graphite is selflubricating andwill not adhere to or corrode the working parts. After the rubber andgraphite have been thoroughly kneaded together the mixture is thenspread in a mold the desired thickness of the covering. For this purposeI employ a mold similar to that used for vulcanizing rubber heels, butof a form which will give the desired shape of packing, which can bemade in a great variety of forms. The thickness of the covering B isalso determined at this stage, and it may be made either thin or thick,according to the use to be made of the finished packing. I next placethe shredded metallic core in the mold on the rubber and envelop itcompletely with the rubber covering, and the whole is subjected to aheavy pressure for the purpose of making the core compact and forcingthe rubber in between the outside shreds of the core. Thus the packingis made in a solid body and will not separate when partially worn out.placed in any'ordinary vulcanizer and the packing is subjected to abaking of from ten to thirty minutes. The length of time depends uponthe kind of packing desired. In order to secure a packingwhich is veryflexig5 ble, with a soft covering, I bake it ten or fifteen minutesonly; but to get a packing with a hard brittle covering it is necessaryto vulcanize it for thirty minutes-or more. When taken from the mold thepacking is ready for ICO use.

In Fig. 1 is an illustration of the application of the packing to thepiston-rod C, the packing being placed within the stuffing-box Afterbeing pressed the mold is D and compressed against the piston-rod by thegland E, Operated by the stud-bolts F F. One or more rings of packingmay be used. As the piston Works there is no friction from the rubbercovering, because the graphite acts as a perfect lubricant even when thepiston becomeshot, and as the covering Wears away the gland istightened, and the piston forms a seat which is absolutely steam-tight.\Vhen the piston has gradually worn away the rubber covering, it exposesthe metal core; but that being of soft, metal will not score thepiston-rod and will operate as a metal packing with a tight-fittingjoint which does not permit the escape of steam. In this way the packingbecomes very durable and efficient.

This semimetallic packing combines all the good features of bothmetallic and soft-fabric packings without any of their disadvantages. Itcan be made in any size and in any form desired, it being necessary toprovidea suitable mold only. If desired, it can be made in sheet form,and gaskets of any size and form may be cut out with a stamp.

My packing can be made soft, like a fabric packing, or hard, resemblinga metal packing, according to the use for which it is designed. Forexample, if the core is made large and a thin covering put on and bakedhard and brittle it can be made more efficient than a metal packing, forthe reason that the rubbercovering next to the working parts beingbrittle soon wears away, leaving a metal contact, and the core beingheld together by the remaining parts of the cover possesses. just enoughflexibility, which is lacking in a metal ring-packing, to respondreadily to the pressure of the gland, and thereby to form a steam-tightjoint.

Obviously my invention can be embodied in many different forms withoutdeparting from the spirit thereof, and I desire to claim my invention inthe broadest mannerlegally possible.

What I claim isl. A packing consisting of a core of metal threads, saidthreads being arranged lengthwise of the core, and a matrix of acomposition of rubber and graphite, said matrix being pressed andvulcanized to the core to hold the metal threads thereof together,substantially as described.

2. A packing consisting of a core of metal threads and a covering of acomposition of rub= her and graphite, said covering being pressed intothe interstices of said core and vulcanized.

3. A packing consisting of a core of metal threads and a matrix of acomposition of rubher and graphite; said matrix filling up theinterstices in said core and intermingling with said metal threads andbeing pressed and vulcanized to hold firmly together the metal threadsof said core.

In testimony whereof I affix my signature in the presence of twowitnesses.

ALBERT L. COLE.

Witnesses:

ARTHUR J. SELFRIDGE, MATTIE A. PROUTY.

